US7743771B2 - Earplug with articulating stem and locking features - Google Patents

Abstract

A hearing protection device is provided including a stem, a protrusion formed on the stem, an articulation point formed on the stem, and a sound attenuating element including a cavity, where the protrusion is disposed in locking engagement within the cavity to releasably attach the stem to the sound attenuating element, and where the stem is configured to at least partially articulate about the articulation point.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation in part of U.S. patent application Ser. No. 11/270,053 filed on 9 Nov. 2005, currently pending, the contents of which are incorporated by reference herein in their entirety.

TECHNICAL FIELD OF INVENTION

The invention concerns hearing protection devices and, more particularly, an earplug, and a stem for an earplug, where the stem includes a locking feature which facilitates assembly of the earplug and enables enhanced comfort to a wearer.

BACKGROUND OF INVENTION

The use of hearing protective and noise attenuating devices is well known, and various types of devices are available including, but not limited to, ear muffs, semi-aural devices, and earplugs. Earplugs are often preferred for their effectiveness in attenuating sound and for comfort properties provided thereby.

An earplug generally comprises a sound attenuating element which is placed in the ear canal of a wearer to occlude the canal and thus provide a desired sound attenuation. The sound attenuating element is commonly made of a compressible, resilient material such as a foam or a rubber.

The earplug may further include a stem extending from the sound attenuating element. The stem serves as a handle to facilitate general tactile manipulation of the earplug. Furthermore, the stem assists during insertion of the earplug into the earcanal by serving as a means for pushing the sound attenuating element to a sufficient depth within the earcanal. Correspondingly, the stem aids in removal of the earplug by providing a grip by which the earplug may be pulled from the earcanal.

The sound attenuating element and the stem of such earplugs may be formed separately and then fixed together or may be integrally formed together. In the case of the former, a rigid or semi-rigid stem is typically embedded partly or entirely within the resilient sound attenuating element. An adhesive is used to fix the stem to the attenuating element or the attenuating element may be formed directly on the stem so as to bond intimately therewith. In either case, manufacture and assembly can be a complicated, multi-step process, perhaps requiring numerous toolings, etc., and resulting in an overall increased cost of the earplug. Moreover, the stems for these types of earplugs are typically quite rigid so as to sustain being inserted within the sound attenuating element and bonded therein. While this relatively increased rigidity facilitates assembly of this traditional earplug, it detracts from the comfort provided thereby to the user by preventing or limiting the ability of the stem and earplug to conform to the natural curvature of the inner ear.

A conventional earplug having an integrally formed (i.e., one-piece) attenuating element and stem is typically pre-molded of a soft rubber-like material. This material is advantageous due to the comfort properties provided thereby. However, the soft rubber material lacks in rigidity and thus can be less effective for inserting the sounding attenuating element to a desired depth within the ear canal. Attempts at increasing the rigidity of the stem of this type of integrally formed earplug may be unsuccessful due to the corresponding stiffening of the sound attenuating element and hence the loss of comfort properties thereof. Some have attempted to add stiffening elements to the stem of integrally formed, pre-molded earplugs. However, this can be a complex assembly process and can result in an overall more expensive earplug. Moreover, the stiffening element is often too long relative to the axis of the earplug and thus cannot easily traverse the bend in the earcanal when inserted or is too short and thus does not properly serve the intended stiffening function.

Thus, an earplug is desired which includes a soft, comfortable sound attenuating element and a stem attached thereto for handling and inserting the earplug, where the stem is sufficiently rigid to enable insertion of the attenuating element to a desired earcanal depth and yet sufficiently pliable to remain comfortable within the ear and to allow the earplug to conform to the natural contours of the earcanal, and where the earplug is capable of being readily manufactured and assembled at a reasonable cost.

BRIEF SUMMARY OF THE INVENTION

The above discussed and other problems and deficiencies of the prior art are overcome or alleviated by the invention which provides a novel and nonobvious hearing protection device.

In one exemplary embodiment, the invention provides a hearing protection device including a stem, a protrusion formed on the stem, an articulation point formed on the stem, and a sound attenuating element including a cavity, where the protrusion is disposed in locking engagement within the cavity to releasably attach the stem to the sound attenuating element, and where the stem is configured to at least partially articulate about the articulation point.

The invention further provides a hearing protection device including an elongated stem member having an attachment portion and a handle portion, a protrusion formed on the attachment portion of the stem member, an area of reduced stem member cross-sectional area delimited by the attachment portion proximate to the protrusion, and a sound attenuating element including a cavity formed at an interior thereof, where the attachment portion is disposed within the cavity, where the protrusion is disposed within the cavity in locking engagement with a mating element of the sound attenuating element to releasably attach the stem member to the sound attenuating element, where the area of reduced stem member cross-sectional area delimits an articulation point of the stem member, and where the stem member and the sound attenuating element disposed thereon are configured to at least partially articulate about articulation point.

The above-discussed and other features and advantages of the apparatus and method of the invention will be appreciated and understood by those skilled in the art from the following drawings and detailed description.

BRIEF DESCRIPTION OF THE FIGURES

Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:

FIG. 1 is a side view of an earplug stem in one embodiment of the invention;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a side view of an earplug having the stem ofFIGS. 1-5;

FIG. 7 is a top view thereof;

FIG. 8 is a bottom view thereof;

FIG. 9 is a rear view thereof;

FIG. 10 is a front view thereof;

FIG. 11 is a perspective view of an attenuating portion of the earplug ofFIGS. 6-10;

FIG. 12 is a side elevation view thereof;

FIG. 13 is a cross-section view thereof;

FIG. 14 is a side view of an earplug in another embodiment of the invention having the stem ofFIGS. 1-5;

FIG. 15 is a top view thereof;

FIG. 16 is a bottom view thereof;

FIG. 17 is a rear view thereof;

FIG. 18 is a front view thereof;

FIG. 19 is a side elevation view of an earplug according toFIGS. 6-10 having a cord attached thereto;

FIG. 20 is a side elevation view of an earplug according toFIGS. 14-18 having a cord attached thereto; and

FIGS. 21-24 are side views of earplugs in other embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERED EMBODIMENT

FIGS. 1-5 shows astem10 for an earplug50 (see,FIGS. 6-10), in one exemplary embodiment of the invention. Thestem10 generally includes ahandle portion12 and aattachment portion14 extending therefrom. As will be discussed herein in detail, theattachment portion14 is particularly configured to include a locking feature which allows thestem10 to be mated with a sound attenuating portion (see,FIGS. 6-10) of theearplug50 without the use of adhesives, in situ molding processes, etc. Thehandle portion12 is configured and oriented to facilitate handling, earcanal insertion, and earcanal removal of theearplug10.

Thehandle portion12 of thestem10 includes aproximate portion16 and an opposingdistal portion18. As shown inFIGS. 1-5, theproximate portion16 is disposed near theattachment portion14. Thedistal portion18 is adjacent to theproximate portion16, opposite from theattachment portion14. Theproximate portion16 extends generally along an axis A-A shared with theattachment portion14. (See, particularly,FIG. 1.) Thedistal portion18 diverges from theproximate portion16 along an axis B-B. The axis B-B is disposed at an angle θ relative to the axis A-A. The angle θ is generally greater than 90° and preferably between 110° and 140°. In the present exemplary embodiment, the angle θ is generally less than or equal to approximately 125°. In other words, in this exemplary embodiment, the axis B-B is not collinear with the axis A-A. Of course, this is merely illustrative. In another exemplary embodiment of the invention, thedistal portion18 may be collinear with theproximate portion16. See, e.g., description below related toFIGS. 21-24.

In the illustrated embodiment, as mentioned, thedistal portion18 of the stem handle12 extends at an angle θ relative to theproximate portion16 and (as will be discussed further herein) relative to theattachment portion14. The result is a substantially pistol-shapedstem10. Due to this unique shape, thestem10 may be advantageously worn by a wearer inconspicuously and in such manner so as to avoid inadvertent contact. That is, when an earplug utilizing thestem10 is inserted into the ear of a wearer, theproximate portion16 of thehandle portion12 extends slightly from the earcanal and the angleddistal portion18 extends in a downward direction from the earcanal and lies discretely in the folds of the outer ear and, particularly, in the tragus area of the ear. This allows the earplug to be worn discretely and disposes thehandle portion12 of thestem10 in a region close to the ear and head of the wearer thus preventing against and minimizing inadvertent contact therewith.

Further advantageously, theangled stem10 provides anangled handle portion12 which is configured to be readily gripped, manipulated, and handled. The unique shape of thestem10 further allows a wearer to twist thestem10 upon inserting the earplug into the earcanal. That is, the angle formed in thestem10 allows the wearer to exert sufficient torque to the earplug upon insertion into the earcanal such that the earplug, and thestem10 particularly, may easily and comfortably traverse the natural bend of the earcanal thus properly disposing the sound attenuating element of the earplug within the earcanal to achieve sufficient occlusion.

Thedistal portion18 of the stem handle12 includes ahandling area20 disposed approximately midway along a length of theportion18. Thehandling area20 comprises a contoured surface for facilitating retention of thestem10 between fingertips of the wearer. For example, thehandling area20 may comprise an oval shaped surface having planar and/or curvilinear features. That is, thehandling area20 may be flat, convex, concave, or any combination of these. Thearea20 may additionally and/or alternatively include grip features which are disposed inset or in relief relative to thefeature20, such as score lines, protuberances, etc. Thehandling area20 may further include indicia, symbols, etc., such as trade names, product names, etc. These may be printed at thehandling area20 or formed thereon in relief or in an inset fashion.

Thedistal portion18, in the exemplary illustrated embodiment, includes anaperture22 formed at an end opposite from theproximate portion16. Theaperture22 extends along the axis B-B, forming a cavity within thedistal portion18. Theaperture22 and resulting cavity are generally circular in cross-section and are configured to receive and retain acord51 as shown inFIG. 19. Thecord51 allows the resultingearplug50 to be attached to anotherearplug50 to form a connected pair ofearplugs50. The cross-section of theaperture22 may be sized slightly smaller than that of thecord51 such that the cord is held therein in a friction fit. Additionally and/or alternatively, thecord51 may be bonded to thedistal portion18 in the aperture by way of an adhesive agent, an in situ molding process, etc. Of course, theaperture22 may be used to house any alternative device or element. For example, a detectable element such as a metallic or magnetic insert, may be disposed within the aperture.

As mentioned, theattachment portion14 of thestem10 includes important and novel features which facilitate attachment of thesound attenuating element52 with thestem10. In this exemplary embodiment, these features include a firstconical portion24 which has a generally serially decreasing circular cross-section and tapers toward a front of theattachment portion14, and a secondconical portion26 adjacent to theportion24 where theportion26 also includes a serially decreasing circular cross-section which tapers in a direction toward the front of theattachment portion14. Theportion14 also includes afront end28 which is generally a cylindrical member extending away from the secondconical portion26. These features24,26, and28 are specifically shaped, disposed, and configured to aid in affixing thesound attenuating element52 to thestem10. Namely, thesefeatures24,26,28 include shapes, surfaces, and dimensions which are readily received and retained by the internal configuration of thesound attenuating element52 to facilitate said affixation.

For example, in this exemplary embodiment, the firstconical portion24 includes a width A′ proximate to thehandle portion12 of about 0.100 inch to about 0.150 inch and preferably about 0.125 inch. The firstconical portion24 tapers inwardly in a direction toward thefront end28 at an angle relative to a longitudinal axis of the firstconical portion24 of about 1 to 5 degrees and preferably of about 3 degrees. The firstconical portion24 generally includes a length C of about 0.250 inch to about 0.300 inch and is preferably about 0.275 inch. The secondconical portion26 includes a width B′ of about 0.150 inch to about 0.200 inch and preferably of about 0.170 inch. The secondconical portion26 further includes a length D of about 0.120 inch to about 0.160 inch and preferably of about 0.145 inch. The secondconical portion26 tapers inwardly in a direction toward thefront end28 at an angle of about 5 to 15 degrees and preferably of about 8 degrees relative to a longitudinal axis of theportion26. Thefront end28 includes a longitudinal length of about 0.200 inch to about 0.250 inch and preferably of about 0.225 inch. A width F of thefront end28 is about 0.050 inch to about 0.100 inch and preferably about 0.080 inch. As shown in the drawings, in this exemplary embodiment, thefront end28 is generally a cylindrically shaped element which extends integrally from the second conical portion.

It is noted that the firstconical portion24 is not entirely conical but instead comprises a portion of a cone. That is, more accurately, the firstconical portion24 comprises a frustum of a cone where the frustum extends between theproximate portion16 of thestem10 and the secondconical portion26. Similarly, the secondconical portion26 is not a complete cone but instead is a frustum of a cone which extends from the firstconical portion24 to thefront end28. Thus, herein theportions24 and26 are referred to as “conical”, but it shall be understood that in this one embodiment of the invention the first and secondconical portions24,26 are actually frusta of respective cones.

Advantageously, the cross-section of the firstconical portion24 varies over its length. Resultantly, a stiffness of the firstconical portion24 correspondingly varies. In the illustrated exemplary embodiment, the cross-sectional area of the firstconical portion24 is greatest proximate to thehandle portion12 of thestem10 and is smallest proximate to the secondconical portion26. Thus, the firstconical portion24 is of a greater stiffness in the area proximate to thehandle portion12 and is of a lesser stiffness at the area proximate to the secondconical portion26. This feature of enhanced stiffness in the area proximate to thestem handle portion12 provides the firstconical portion24 with a sufficient rigidity to enable proper insertion of theattachment portion14 of thestem10 into the earcanal. Yet, the reduced stiffness of the first conical24 in the area proximate the secondconical portion26 allows theattachment portion14 to bend when thestem10 is inserted into the earcanal thus permitting the stem to conform to the natural contour and curvature of the earcanal. Particularly, the reduced thickness of the firstconical portion24 at the secondconical portion26 acts as a hinge point or point of articulation which allows the secondconical portion26 and thefront end28 to pivot and articulate relative to the firstconical portion24 and thehandle portion12 of thestem10. Thus, as theattachment portion14 enters the earcanal, theattachment portion14 is configured to articulate about the area of reduced cross-sectional area of the firstconical portion24 proximate to the secondconical portion26.

Thefront end28 of thestem attachment portion14, as mentioned, comprises a generally cylindrical member which extends from the secondconical portion26 to a terminable end of theearplug stem10. Thisfront end28 comprises a reduced stiffness such that thefront end28 is capable of articulating during insertion of thestem10 into the earcanal. This articulation allows theinsertion portion14 of thestem10 to easily follow the contour and curve of the earcanal during earplug insertion. Thus, a sufficient depth of insertion may be achieved to provide optimized occlusion while providing the wearer with enhanced comfort properties.

The secondconical portion26 has a stiffness greater than that of the firstconical portion24 and greater than that of thefront end28. This enables theattachment portion14 of thestem10 to articulate at at least two points: (1) an area of the firstconical portion24 proximate to the secondconical portion26; and (2) an area of thefront end28 proximate to the secondconical portion26. That is, in a sense, the more rigid secondconical portion26 serves as a joint about which the firstconical portion24 and/or thefront end28 may articulate and pivot. Also, as discussed further herein in detail, the second conical portion is configured to be received and retained within a sound attenuating portion of a resulting earplug. Particularly, the secondconical portion26 is configured to attain a friction fit within the sound attenuating portion.

FIGS. 6-10 show theearplug50 having thesound attenuating element52 attached to thestem10. Here, by way of example, thesound attenuating element52 is shown as comprising a plurality of rearwardly facingsemi-hemispherical flanges54. Threesuch flanges54 are shown. Of course, theearplug50 may include more or less of the flanges54 (e.g., four or more flanges, two flanges, a single flange, etc., seeFIGS. 14-18 and20 for an alternate embodiment). Abase56 of the sound attenuating element is disposed partly on theproximate portion16 of thestem10. Here, thesound attenuating element52 may be formed of a thermoplastic elastomer (TPE), or any suitable compressible material. Thesound attenuating element52, for example, may be similar or identical to that disclosed in U.S. Pat. No. 4,867,149, issued on Sep. 19, 1989, the contents of which are herein incorporated by reference in their entirety.

Thesound attenuating element52 may be pre-molded and then is preferably affixed to thestem10 by a friction/snap fit. In such embodiment, the attenuatingelement52 is formed with a receptacle at its interior generally configured to receive and retain theattachment portion14 of thestem10. As discussed in detail below, the receptacle may have a cross-sectional area smaller than that of theattachment portion14 of thestem10 such that the friction fit is establish upon inserting thestem10 into the receptacle. Additionally, the attachment features24,26,28 of theattachment portion14 may be configured to mate or create a snap-fit with the interior of thesound attenuating element52 at the receptacle. That is, theportion14 and the receptacle can include interlocking features such as male and female elements, etc.

FIGS. 11-13 show various views of thesound attenuating element52. Theelement52 includes anaperture30 which opens to acavity32 within thesound attenuating element52. See, particularly,FIGS. 11 and 13. Thecavity32 includes a generally circular cross-section and extends inwardly along a longitudinal axis X-X of thesound attenuating element52. Theaperture30 is disposed at a bottom surface of thebase56 and provides an opening between thecavity32 and an exterior of thesound attenuating element52. Thecavity32 extends through thebase56 and terminates at an area beneath one of theflanges54, particularly, beneath amiddle-most flange54 as shown inFIG. 13. Thecavity32 includes a roundedarea34 at the point of termination of thecavity32. The rounded area may be hemispherical, semi-hemispherical, or otherwise curved or angled as desired.

Thecavity32 includes achamber36 disposed about mid-length along thecavity32. Thechamber36 is essentially a portion of thecavity32 having a greater cross-sectional width than the remaining portions of thecavity32. In this exemplary embodiment, thechamber36 includes a circular cross-section greater than that of thecavity32. Thechamber36 is particularly configured and disposed to receive and retain the secondconical portion26 of thestem10, as will be further discussed herein. Thechamber36 extends along the axis X-X of thesound attenuating element52 and is disposed generally concentric with thecavity32. That is, thechamber36 is disposed between arearward portion33 and aforward portion35 of thecavity32. Thechamber36 includes afirst seat38 which extends around one end of thechamber36 proximate to therearward portion33 of thecavity32. Thechamber36 further includes a correspondingsecond seat40 disposed at the interface of thechamber36 and theforward portion35 of thecavity32.

As mentioned, thecavity32 and thechamber36 are particularly configured and disposed to receive and retain the attachment portion of the14 of thestem10. That is, theattachment portion14 is designed to mate and engage with thecavity32 andchamber36 such that thesound attenuating element52 is fixedly attached to thestem10 without the use of adhesives, welding, bonding, etc. Instead, a reliable friction-fit and/or snap-fit is established between the attenuatingelement52 and theattachment portion14 of thestem10.

When theattachment portion14 of thestem10 is fully inserted within thecavity32, the firstconical portion24 is disposed within therearward portion33 of thecavity32 nearest theaperture30, the secondconical portion26 is disposed within thechamber36, and thefront end28 of theattachment portion14 is disposed withinforward portion35 of thecavity32 nearest the roundedarea34. See,FIGS. 1 and 13.

Thecavity32 includes a width P which is equal to or less than the widths A′ and F of the firstconical portion24 and thefront end28, respectively. For example the width P is approximately less than or equal to about 0.150 inch. More particularly, the width P is about 0.050 inch to about 0.100 inch and is preferably about 0.080 inch. The rearward andforward portions33,35 of thecavity32 include a length sufficient to receive and retain the relevant portions of theattachment portion14 of thestem10. For example, therearward portion33 of thecavity36 includes a length Q of about 0.250 inch to about 0.300 inch and preferably of about 0.280 inch. Theforward portion35 of thecavity32 includes a length R of about 0.200 inch to about 0.300 inch and preferably of about 0.300 inch. Theforward portion35 of thecavity32 includes the roundedarea34 to receive a tip of thefront portion28 of thestem attachment portion14 because this tip may be correspondingly rounded or may angled, etc., or may include protuberances, screw threads, etc.

Thechamber36, as described, is a substantially cylindrical orifice disposed along thecavity32 between the forward andrearward portions33 and35 thereof. Thechamber36 is shaped and dimensioned to receive and retain the secondconical portion26. In this embodiment of the invention, thechamber36 includes a circular cross-section equal to or less than that of the secondconical portion26. For example, the chamber may include a width T of less than or equal to about 0.200 inch. For example, the width T may be about 0.160 inch to about 0.120 inch and, more preferably, may be about 0.140 inch. A length S of thechamber36 is of sufficient dimension to receive the length D of the secondconical portion26. For example, the length S may be about 0.120 inch to about 0.160 inch and, more preferably, is about 0.145 inch.

Notably, the disposition of thechamber36 relative to the reward andforward portions33 and35 of thecavity32 creates the first andsecond seats38 and40, respectively, both having a dimension U of about 0.040 inch to about 0.080 inch and, more preferably, of about 0.060 inch.

As mentioned, when thesound attenuating element52 is properly mated with theattachment portion14 of thestem10, the secondconical portion26 is disposed within thechamber36. In this configuration, the width B′ of the secondconical portion26 is disposed adjacent to and engages against theseats38 of thechamber36. Because the dimension B′ of theportion26 is generally and preferably greater than the width T of thechamber36, the secondconical portion26 is held fixedly and is retained within thechamber36. In this way, theattachment portion14 of thestem10 is essentially locked within the interior of thesound attenuating element52 thus forming theearplug50.

As discussed herein, thesound attenuating element52 is made of a flexible, stretchable elastomer material. Accordingly, the portions of the attenuatingelement52 which delimit thechamber32 are capable of stretching around the firstconical portion24 and thefront end28 when such are disposed, respectively, within therearward portion33 and theforward portion35 of thecavity32.

Assembly of theearplug50 is commenced by first inserting thefront end28 of thestem attachment portion14 into theaperture30 disposed at thebase56 of thesound attenuating element52. Thefront end28 is passed into therearward portion33 of thecavity32. As theattachment portion14 is moved further into thecavity32, the secondconical portion26 engages thesound attenuating element52 proximate to theaperture30.

Typically, as discussed above, the width B′ of the secondconical portion26 is greater than the width P of the cavity. Accordingly, the secondconical portion26 resists forward movement of theattachment portion14 into thecavity32. However, the tapered shape of the frustum forming the secondconical portion26 and the stretchable nature of thesound attenuating element52 combine to allow entry of theportion26 into therearward portion33 of thecavity32. That is, a width of the secondconical portion26 opposite from the width B′ is less than the width B′ and is generally less than the width P of thecavity32. In this way, a forward end of the secondconical portion26 may enter thecavity32. Then, as theattachment portion14 is pressed further into thecavity32, the angled sides of the secondconical portion26 uniformly expand thesound attenuating element52 about therearward portion33 of thecavity32 until theportion26 is fully disposed within therearward portion33. Generally, at this point thefront end28 enters and passes through thechamber36. Then, theattachment portion14 is pressed further into thecavity32 until the secondconical portion26 is received within thechamber36.

As mentioned, as the width B′ of the secondconical portion26 passes through therearward portion33 of thecavity32, the proximate portions of thesound attenuating element52 are pressed outwardly to accommodate said passage. When the width B′ engages thefirst seat38 of thechamber36, theseat38 may yield to the outward pressure exerted by the width B′, such that the secondconical portion26 is rapidly positioned within thechamber36. This rapid positioning defines the snap-fit feature mentioned above with respect to the attenuatingelement52 and thestem10. That is, to assemble theearplug50, theattachment portion14 of thestem10 is essentially pressed into thecavity32 of the attenuatingelement52 until the secondconical portion26 snaps into, i.e., locks into place and is fully received within, thechamber36. This snap-fit feature provides a tactile indication to the assembler that thestem10 is properly mated within thesound attenuating element52.

As noted, the length D of the secondconical portion26 is generally greater than the length S of thechamber36. Thus, upon entry of the secondconical portion26 into thechamber36, areas of thesound attenuating element52 proximate thechamber36 are forced to expand. This expansion results naturally in a compressive reaction force which acts upon the secondconical portion26 and serves to hold theportion26 firmly and securely within thesound attenuating element52.

When disposed within thechamber36, the width B′ of the secondconical portion26 buts theseat38. Because the width B′ is greater than the width P delimited by theseat38 and therearward portion33 of thecavity32, theattachment portion14 of thestem10 resists backward movement relative to thesound attenuating element52. That is interaction of the secondconical portion26 and theseat38 prevents theattachment portion14 from withdrawing from thecavity32. In this way, thestem10 is essentially locked within the sound attenuating element. That is, thestem10 is securely fixed therein without requiring the use of adhesives or without having the attenuatingelement52 formed directly on or otherwise bonded directly to thestem10.

Upon entry of the secondconical portion26 into thechamber36, thefront end28 of thestem attachment portion14 is placed within theforward portion35 of thecavity32. Correspondingly, at this point, the firstconical portion24 enters and becomes fully disposed within therearward portion33 of thecavity32. As discussed above, the width A′ of the firstconical portion24 is generally greater than the width P of thecavity32. Thus, upon insertion of the firstconical portion24 into therearward portion33 of thecavity32, proximate areas of the attenuatingelement52 stretch outwardly to accommodate theportion24. This creates a pressure upon the firstconical portion24 which assists in holding theportion24, and theentire attachment portion14, firmly within thecavity32. This contributes to the friction-fit existing between thestem10 and thesound attenuating element52.

In the illustrated exemplary embodiment of the invention, the secondconical portion26 of theattachment portion14 of thestem10 is disposed at an approximate mid-point of a longitudinal length of the sound attenuating element25 when thestem10 is disposed therein. See, e.g.,FIG. 13. This creates an advantageous point of articulation at an area generally midway between a front and rear of the sound attenuating element25. The positioning of the secondconical portion26 within the sound attenuating element25 corresponds to an approximate first bend of a typical earcanal. Thus, theearplug50 is particularly suited for being inserted into the earcanal and traversing this first bend in the earcanal due to the articulation property of theattachment portion14 of thestem10. This allows easy insertion of theearplug50 to a sufficient depth within the earcanal and results in a comfortable occlusion of the earcanal once inserted. The disposition of the secondconical portion26 within thesound attenuating element52 further ensures that the approximate center of mass of the element25 (in combination with the underlying stem attachment portion14) lies in front of thehandle portion12 of thestem10. This results in thewearer grasping earplug50 via thehandle portion14 at position behind the center of mass of the inserted portion of the earplug. Thus, theearplug50 is readily manipulated and easily driven into the earcanal.

Thesound attenuating element52 has been discussed and shown herein by way of example as including the threesemi-hemispherical flanges54. It shall be appreciated that the broad scope of the invention contemplates a sound attenuating element of any one of a variety of configurations and/or constructions. For example, in another embodiment of the invention shown inFIGS. 14-18 and20, anearplug110 is provided including astem100 and asound attenuating element112. Thestem100 andsound attenuating element112 are similar in many respects to thestem10 and attenuatingelement52, respectively, which are discussed above. Features which are consistent between the various embodiments of the invention discussed herein are indicated by consistent reference numerals and, for sake of brevity, are not reintroduced or discussed in substantive detail.

Thestem100 includes thehandle portion12 extending along the axis B-B and theattachment portion14 extending along the axis A-A, where the axes intersect at the angle θ. The attenuatingelement112 is affixed to thestem100 over the attachment portion14 (not shown) in similar fashion as described above with respect to theearplug10. That is, the attenuatingelement112 includes a channel and receptacle disposed and configured to receive and retain theattachment portion14 of thestem100 in snap-fit and/or friction-fit arrangement. See discussion above pertaining to theearplug10.

A rear114 of thesound attenuating element112 proximate to thehandle portion12 of thestem100 is essentially an outwardly extending flange element, as shown in the drawings, which is configured to seal the ear canal of a wearer when theearplug110 is inserted therein. Afront116 of thesound attenuating element112 includes a rounded shape, such as a semi-hemispherical, semi-elliptical, etc. shape, in order to facilitate insertion of theearplug110 into the ear canal. Thesound attenuating element112 further includes a taperedportion118 disposed between the front116 and rear114. The taperedportion118 is an area of reduced cross-sectional area which extends generally in a middle portion of thesound attenuating element112. Of course, theelement112 may alternatively include a substantially cylindrical shape of generally uniform cross-sectional diameter. Still further, thesound attenuating element112 may comprise spherical shape, a rearwardly extending flange shape, or any desired shape and/or configuration.

Like theearplug50, theearplug110 includes theaperture22 formed in thestem100 for receipt and retention of a cord101, as shown inFIG. 20. The cord101 is configured to be similarly attached to asecond earplug110 to thus form a corded pair ofearplugs110. The cord101 may be friction fit within theaperture22 or bonded to or molded therewith.

An interior (not shown) of thesound attenuating element112 is substantially similar to that of thesound attenuating element52. That is, the attenuatingelement112 includes thecavity32 and thechamber36 disposed between rearward andforward portions33 and35 of thecavity32. As in theearplug10, thecavity32 andchamber36 are particularly disposed, configured, and dimensioned within thesound attenuating element112 to receive and retain theattachment portion14 of thestem110 in order to provide the friction-fit and/or snap-fit between theelement112 and thestem110. Reference is made herein to the above-provided descriptions.

Thesound attenuating element112 of theearplug110 is formed preferably of a compressible, resilient slow-recovery foam material such as polyvinylchloride (PVC) or polyurethane. For example, thesound attenuating element112 may be composed of a material as that described in U.S. Pat. No. Re. 29,487 issued on Dec. 6, 1977, the contents of which are herein incorporated by reference in their entirety.

Thehandle portion12 of theearplugs50,110 described herein may be substantially cylindrical in shape, having a generally consistent cross-sectional diameter across its length. Alternatively, thehandle portion12 can include cross-sections of variable diameter such that an area(s) of thehandle12 tapers inwardly and/or outwardly. In another embodiment, the handle portion includes a rectilinear or elliptical cross-section of consistent or variable cross-sectional area. Further, thehandle portion12 may include a combination of some or all of these configurations and/or further configurations as desired.

Thehandle portion12 of the invention has thus far been described as being composed of intersecting substantially linear proximate anddistal portions16 and18, respectively. In another embodiment of the invention, thehandle portion12 of thestem10,100 extends in a curvilinear fashion from thesound attenuating element52,112. That is, in such embodiment, the handle portion is at least partially rounded such that theportion12 curves away from the longitudinal axis A-A of theattachment portion14 and of thesound attenuating element52,112.

For example,FIG. 21 shows anearplug200 having thesound attenuating element52 attached to astem202. Thestem202 includes the attachment portion14 (not shown) and acurved handle204. Thehandle204 traces a curve which, for example, may be a portion of a radius of a circle, a portion of an ellipse, or any other desired curve.FIG. 22 shows anearplug250 in another embodiment of the invention. Theearplug250 includes astem252 which includes the attachment portion14 (not shown) affixed to thesound attenuating element52 and which further includes acurvilinear handle254 extending therefrom. Thehandle254 traces a substantially serpentine pattern, i.e., an approximately S-shaped pattern.

FIG. 23 shows anearplug300 in another embodiment of the invention. Theearplug300 includes thesound attenuating element52 and astem302 extending therefrom. Thestem302 includes the attachment portion14 (not shown) and ahandle portion304 extending from the attenuatingelement52. Thehandle portion304 extends in a substantially linear fashion along the axis B-B which forms the angle e with the axis A-A of thesound attenuating element52. That is, thehandle portion304 is similar to thehandle portion14 of thestem10 except that, here, thehandle304 does not include a proximate portion collinear with the attenuating element as does thestem10. To the contrary, the entirety of thehandle304 extends angularly relative to the sound attenuating portion.

Another alternate embodiment of the invention is shown inFIG. 24. Therein, anearplug500 includes thesound attenuating element52 attached to astem502 having ahandle portion504. Here, thehandle portion504 and attachment portion14 (not shown) are collinear and extend along the axis A-A of the attenuatingelement52.

In all of these alternate embodiments, the stems202,252,302, and502 are attached to thesound attenuating elements52 by way of the above-discussed interaction between thecavity32 andchamber36 of thesound attenuating elements52 and the locking features24,26, and28 of theattachment portions14 of the respective stems. That is, eachstem202,252,302, and502 includes the firstconical portion24, the secondconical portion26, and thefront end28 which are configured to mate securely with thecavity32 and thechamber36 as discussed above. Thus, theearplugs200,250,300, and500 are assembled by first manufacturing the respective stems202,252,302, and502 and thesound attenuating elements52 and then inserting thefront end28 of each stem into theparticular cavity32 and pressing until the secondconical portion26 is fixedly disposed in thechamber36.

It is noted that the stem handles204,254, and304 of theearplugs200,250, and300, respectively, are shown in the drawings as having a circular cross-section which is of consistent shape and size across a length of the handle. Alternatively, of course, thehandles204,254,304 may comprise a variably shaped and/or sized cross-section. Thehandles204,254,304 can additionally and/or alternatively comprise thehandling area20 and theaperture22 for receipt and retention of a cord.

Thesound attenuating elements52,112 discussed herein may be of the push-in type, the roll-down type, or the partial roll-down type. That is, thesound attenuating elements52,112, in one embodiment, are inserted into the ear canal by simply placing the element at the entrance of the canal and pushing inwardly on thehandle portion12 of thestem10,100. In another embodiment, thesound attenuating element52,112 is rolled between the fingers in order to fully compress theelement52,112 against theattachment portion14 of thestem10,100 prior to insertion of theelement52,112 into the ear canal. In a further embodiment, the attenuatingelement52,112 is compressed only partially prior to insertion.

The various stems10,100,202,252,302, and502 described herein may be formed of a plastic or rubber material and may be formed through a molding process, and particularly, by an injection molding process.

The features of the stems10,100,202,252,302, and502 responsible for locking the stems within the interior of thesound attenuating elements52 and112 have been described herein by way of example only. That is, the firstconical portion24, and the secondconical portion26, and thefront end28 and the correspondingcavity32,chamber36, androunded portion34 are merely illustrative of the broad inventive concept of providing an earplug composed of a stem and an attenuating element which are securely attachable without use of an adhesive of other bonding techniques. For example, the stem of the invention may comprise any type of protrusion without limitation configured to be received and retained within a cavity of the sound attenuating element. Such protrusion may be curvilinear or rectilinear in shape or a combination thereof. The protrusion, for example, may include a spherical or semi-spherical shape and the cavity may include a corresponding spherical or semi-spherical shape of a slightly smaller dimension than that of the protrusion such that the protrusion may be lockingly received in a friction-fit within the cavity. Alternatively, the protrusion may be substantially pyramidal, etc. and shape and the corresponding cavity may be similarly shaped to provided the desired mating of the stem and attenuating element. The stem protrusion may have a smooth outer surface (as seen in the secondconical portion26 described herein) or may include additional locking features such as ridges, ribs, protuberances, barbs, screw threads, etc. to further provide locking engagement between the stem and the attenuating element. Additionally and/or alternatively, the portions of the sound attenuating element which form the cavity may include said additional locking features.

Accordingly, the invention results in a hearing protection device, particularly an earplug, which includes a soft compressible sound attenuating element and a more rigid stem where the stem is attached to the sound attenuating element by locking features disposed on the stem and/or on the sound attenuating element such that adhesives, bonding, welding, etc., are not required in assembling the earplug. The resulting earplug includes a stem which is sufficiently rigid to facilitate insertion of the earplug into the earcanal by which remains sufficiently pliable to bend within the earcanal according to the natural contours of the inner ear. This stem is easily attachable to the soft compressible attenuating element to provide an earplug which is very comfortable to the wearer, easily insertable, and which may be readily assembled at a respectively lower cost without the use of adhesives, bonding or welding techniques, etc.

Dimensions and materials identified in this description and the attached Figures are for illustration purposes only and may vary depending upon the intended application in accordance with the teachings of the present invention. The present invention is not intended to be limited to the specific features of the Figures even though the invention encompasses the same.

Furthermore, it will be apparent to those skilled in the art that, while exemplary embodiments have been shown and described, various modifications and variations can be made to the present apparatus and method disclosed herein without departing from the spirit or scope of the invention. Accordingly, it is to be understood that the various embodiments have been described by way of illustration and not limitation.

Claims (20)

1. An hearing protection device, comprising:

a stem;

a protrusion formed on the stem;

an articulation point formed on the stem; and

a sound attenuating element including a cavity;

wherein the protrusion is disposed in locking engagement within the cavity to releasably attach the stem to the sound attenuating element; and

wherein the stem is configured to at least partially articulate about the articulation point.

2. The hearing protection device ofclaim 1, wherein the articulation point comprises an portion of the stem having a reduced cross-sectional area.

3. The hearing protection device ofclaim 2, wherein the portion of reduced cross-sectional area is disposed proximate to the protrusion.

4. The hearing protection device ofclaim 1, wherein the stem includes a serially decreasing cross-sectional diameter in a direction toward the protrusion and wherein an portion of least cross-sectional area delimits the articulation point proximate to the protrusion.

5. The hearing protection device ofclaim 1, wherein the stem comprises a substantially conical shape having an end disposed proximate to the protrusion, wherein the end comprises a portion of the stem of reduced cross-section, and wherein the end delimits the articulation point.

6. The hearing protection device ofclaim 1, wherein the stem comprises a conical portion including an end disposed adjacent to the protrusion, the stem further comprising a cylindrical portion extending from the protrusion opposite from the conical portion.

7. The hearing protection device ofclaim 6, wherein the end is an area of the conical portion having a reduced cross-sectional area, said end delimiting the articulation point.

8. The hearing protection device ofclaim 6, wherein the cavity of the sound attenuating element is configured to receive and releasably retain the cylindrical portion and at least part of the conical portion.

9. The hearing protection device ofclaim 8, wherein the protrusion is disposed at approximately a midpoint of a length of the sound attenuating element such that the stem and the sound attenuating element are articuable about said midpoint.

10. The hearing protection device ofclaim 6, wherein the protrusion comprises a conical shape having a base adjacent to the conical portion, said end being adjacent to the cylindrical portion.

11. The hearing protection device ofclaim 1, wherein the stem comprises an attachment portion having the protrusion formed thereon and configured to be disposed within the sound attenuating element.

12. The hearing protection device ofclaim 11, wherein the stem further comprises a handle portion including grip features to facilitate handling the stem.

13. The hearing protection device ofclaim 12, wherein the attachment portion extends generally along a first longitudinal and the handle portion extends generally along a second longitudinal axis, wherein said first and second longitudinal axes are not collinear.

14. The hearing protection device ofclaim 13, wherein the second longitudinal axis extends from the first longitudinal axis at an angle of approximately less than or equal to 125 degrees.

15. The hearing protection device ofclaim 14, wherein the attachment portion comprises an area of reduced cross-section disposed proximate to the protrusion, wherein said area of reduced cross-section delimits said articulation point.

16. The hearing protection device ofclaim 14, wherein the attachment portion comprises a conical portion including an end disposed adjacent to the protrusion, the attachment portion further comprising a cylindrical portion extending from the protrusion opposite from the conical portion, wherein, said end delimits the articulation point.

17. A hearing protection device, comprising:

an elongated stem member including an attachment portion and a handle portion;

a protrusion formed on the attachment portion of the stem member;

an area of reduced stem member cross-sectional area delimited by the attachment portion proximate to the protrusion; and

a sound attenuating element including a cavity formed at an interior thereof;

wherein the attachment portion is disposed within the cavity;

wherein the protrusion is disposed within the cavity in locking engagement with a mating element of the sound attenuating element to releasably attach the stem member to the sound attenuating element;

wherein the area of reduced stem member cross-sectional area delimits an articulation point of the stem member; and

wherein the stem member and the sound attenuating element disposed thereon are configured to at least partially articulate about the articulation point.

18. The hearing protection device ofclaim 17, wherein the attachment portion extends generally along a first longitudinal and the handle portion extends generally along a second longitudinal axis, wherein said first and second longitudinal axes are not collinear.

19. The hearing protection device ofclaim 18, wherein the second longitudinal axis extends from the first longitudinal axis at an angle of approximately less than or equal to 125 degrees.

20. The hearing protection device ofclaim 17, wherein the attachment portion comprises a conical portion including an end disposed adjacent to the protrusion, the attachment portion further comprising a cylindrical portion extending from the protrusion opposite from the conical portion, wherein, said end delimits the area of reduced stem member cross-sectional area and the articulation point.

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